President Trump refers to a map, modified using a Sharpie, while talking to reporters following a briefing from officials about Hurricane Dorian in the Oval Office at the White House on Sept. 4. (Chip Somodevilla/Getty Images)

A letter sent Thursday from the chair of the House Science Committee to Commerce Secretary Wilbur Ross reveals that it was the Commerce Department, not the leadership of its National Oceanic and Atmospheric Administration, that drafted a controversial NOAA statement on Sept. 6 that backed President Trump’s false statement about the path of Hurricane Dorian. That statement contradicted NOAA’s own meteorologists at a weather forecast office in Birmingham, Ala.

The unsigned statement has generated at least three investigations, including one by the Science Committee, another by NOAA’s chief scientist, as well as the Commerce Department’s inspector general. The new letter, from Committee Chair Eddie Bernice Johnson (D-Tex.), contains previously unknown information about how that statement — which may have violated NOAA’s scientific integrity policy — was written.

The background

Trump wrongly tweeted that Alabama would “most likely be hit (much) harder than anticipated” on Sept. 1 even when the state was not within the National Hurricane Center’s “cone of uncertainty” — the zone most likely to be affected. The National Weather Service forecast office in Birmingham, responding to an influx of calls from worried residents in the wake of the president’s tweet, issued a tweet of its own saying Dorian would not affect Alabama.

At the time, the NWS’s forecast guidance showed only a very small risk (about 5 percent) of tropical-storm-force winds for a small portion of Alabama.

Trump’s tweet that Alabama would be affected by the storm gained national attention when, during an Oval Office press availability, he presented the version of the forecast cone from Aug. 29, extended into Alabama — modified using a Sharpie. The crudely altered map appeared to represent an effort to retroactively justify the original Alabama tweet.

The players

The new letter reveals that the drafting process for the NOAA statement, which rebuked the Birmingham forecast office for speaking “in absolute terms,” was orchestrated by three of Ross’s top deputies, including his chief of staff.

According to the letter, that information was passed on to the Science Committee by Neil Jacobs, acting head of NOAA, in an interview with committee staff last week. Now the Science Committee is asking for interviews with the Commerce Department officials as well as communications concerning the NOAA statement and drafts of it.

In addition, Jacobs told the Science Committee that White House acting chief of staff Mick Mulvaney was “involved in high-level conversations” about the statement, through the Commerce Department officials. As The Washington Post has previously reported, Mulvaney was acting at the request of Trump.

Jacobs reported that he was first contacted about issuing the statement during the predawn hours of Sept. 6 by Michael Walsh Jr., chief of staff to Ross, and that the statement was drafted on the computer of Dave Dewhirst, deputy general counsel at the Commerce Department.

Jacobs said Commerce political staff provided feedback on the draft statement and that Earl Comstock, the agency’s director of policy, was also involved. Within NOAA, Julie Kay Roberts, another political appointee who serves as Jacobs’s deputy chief of staff and communications director, was also engaged in drafting the statement, Jacobs said.

Aside from Jacobs himself, who holds a PhD in meteorology, none of the individuals involved in its drafting is a scientist. NOAA’s scientific integrity policy prohibits political interference with the conduct and communication of the agency’s scientific findings.

Jacobs had fought issuing the statement and also tried to block the paragraph that admonished the National Weather Service office in Birmingham that tweeted that Alabama would “NOT see any impacts” from Hurricane Dorian. However, Jacobs lost both those arguments, according to two people familiar with the matter who spoke to The Post.

The Science Committee letter was a follow-up to a letter sent on Sept. 11 to Ross requesting answers to questions and documents pertaining to Trump’s tweet and the events that followed. The Sept. 11 letter requested a response from the Commerce Department by Sept. 20, but Thursday’s letter noted that the Committee “has yet to receive any responsive materials” and asked for them “as soon as possible” — no later than Oct. 18.